Method of devolatilizing recycled carbon black and associated apparatus

ABSTRACT

A method for controlling volatiles in recycled carbon black, such as from pyrolysis of tires, includes deagglomerating the recycled carbon black to substantially reduce the carbon black particle size and impinging an air current on the carbon black particles, preferably in a countercurrent direction, to increase the processing temperature and thereby enhance the release of volatiles. Associated apparatus is disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional application of U.S. patentapplication Ser. No. 11/715,162, filed Mar. 7, 2007 now U.S. Pat. No.8,263,038, and entitled “Method of Devolatilizing Recycled Carbon Blackand Associated Apparatus,” which claims the benefit of U.S. ProvisionalPatent Application Ser. No. 60/792,992, filed Apr. 18, 2006, andentitled “Methods of Devolatilizing Recycled Carbon Black and AssociatedApparatus.”

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and associated apparatus forcontrolling the volatile level in recycled carbon black material, suchas that obtained from pyrolysis of vehicle tires, and more particularly,it relates to a reduced energy system for obtaining recycled carbonblack of the desired quality.

2. Description of the Prior Art

In view of the increased environmental concerns and the focus uponefficient use of energy, there has been great interest in recycling ofpneumatic vehicle tires in order to obtain reusable products, such ascarbon black

It has been known to employ pyrolysis in order to convert the long chainelastomers and other chemicals in the tires into more volatile fragmentsfollowed by volatilizing these fragments. U.S. Pat. Nos. 6,833,485 and6,835,861 disclose the use of low temperature and low-energy pyrolysisin achieving these objectives.

A thermodynamic analysis of pyrolysis of tire rubbers was disclosed in“A New Method for DTA Measurement of Entropy Change during the Pyrolysisof Rubbers”, Yang et al., Thermochimica Acta 288 (1996), Pages 155-168.

In spite of these prior teachings, there remains a very real andsubstantial need for improved efficiency in pyrolysis recycling of tiresand other waste materials that contain polymers, such as plastics andcarpet.

SUMMARY OF THE INVENTION

The present invention has provided an improved method and associatedapparatus for controlling volatiles in recycled carbon black. The carbonblack is subjected to turbulent mechanical deagglomeration to reduceparticle size after which the reduced-size, recycled carbon blackparticles are subjected to air flow to increase the temperature and,therefore, enhance volatile stripping efficiency due to both the reducedcarbon black particle size and the increased temperature. This ispreferably accomplished at an elevated temperature.

It is preferred to process the tires or tire fragments in a firstreactor during pyrolysis and then introduce the thus processed recycledcarbon black into a second reactor where deagglomeration and elevatedtemperature air flow devolatilization occurs. It is preferred that theparticles subsequently be cooled. The particles entering the secondreactor may have a size in the range of about 100 to 25000 microns andpreferably about 50 to 5000 microns. The particles which have beenmechanically deagglomerated and devolatilized may have a size in therange of about 20 to 200 microns and preferably about 5 to 100 microns.The smaller particles are more amenable to devolatilization at elevatedtemperatures.

In a preferred embodiment of the invention, the mechanicaldeagglomeration may be effected employing an auger which is rotating ata rapid rate and may be inclined from the entry upwardly toward theexit. The air which impinges on the recycled carbon black particles ispreferably blowing in a countercurrent direction with respect to thedirection of flow of the recycled carbon black particles. In anotherembodiment, co-current flow of air and recycled carbon black may beemployed.

It is an object of the present invention to provide an improved methodand associated apparatus for deagglomerating and devolatilizing recycledcarbon black obtained from pyrolysis of tires.

It is another object of the present invention to employ low temperaturepyrolysis while efficiently devolatilizing the recycled carbon black.

It is yet another object of the present invention to employ a localizedhigh temperature zone in a reactor having mechanical means fordeagglomeration in order to provide enhanced volatile stripping of thedeagglomerated recycled carbon black particles.

It is another object of the present invention to provide preciselycontrolled volatilization of organic components of the recycled carbonblack particles in order to establish consistency of the final product.

It is another object of the invention to employ air flow, which ispreferably countercurrent to the direction of flow of the recycledcarbon black, in order to establish a high temperature zone for enhanceddevolatilization.

It is yet another object of the present invention to produce a carbonblack which has a structure and surface area similar to that of virgincarbon black.

These and other objects of the invention will be more fully understoodfrom the following description of the invention with reference to thedrawings appended hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a system of the present inventionemployable in the practice in the method of the present inventionshowing a pyrolysis reactor, a deagglomerator, countercurrent air flowand associated apparatus.

FIG. 2 is a schematic cross-sectional illustration showing a portion ofthe auger of FIG. 1

FIG. 3 is a schematic illustration of a system of the present inventionfor practicing the method of the present invention showing the airintroduction at a different location from that of FIG. 1 for co-currentair flow.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides an improved method for volatilizingrecycled carbon black particles by mechanically deagglomerating theparticles in order to reduce particle size and establishing a hightemperature zone with enhanced stripping of the volatiles from thereduced-size, recycled carbon black particle.

A feature of the present invention is a temperature and residence timehigh enough to break down polymer bonds, but low enough such that cokeformation is minimized. One measure of the efficiency of pyrolysis isthe percentage of volatiles that are retained on the waste materialafter pyrolysis. A second measure is low coke, or non-carbon blackdeposits on the final product. Carbon black is the major component ofthe solids produced from pyrolyzing tires. Some carbon black obtainedfrom pyrolyzing tires contains coke which makes the carbon black lessdesirable for reuse due to the lack of structure and surface areasimilar to virgin carbon black.

In a preferred embodiment of the invention, the recycled carbon black tobe processed will be carbon black obtained from the pyrolysis ofvehicular tires, such as pneumatic tires, or tire shreds. Mechanicalenergy such as energy applied through an auger or a jet of pressurizedair or gas serves to deagglomerate the recycled carbon black as receivedfrom the upstream pyrolysis reactor. Other means of deagglomerating thecarbon black, such as high speed rotating apparatus on a fluid bedreactor, may be employed. Two or more of the foregoing may be employedin combination, if desired. It is preferred that there be a direct feedof the recycled carbon black from the first pyrolysis reactor to thesecond reactor, wherein the deagglomeration and volatilization areachieved. As an alternative, recycled carbon black may be otherwiseindependently delivered to the second reactor.

The deagglomeration serves to reduce the particle size in order toenhance the heat exchange with the air stream which is preferablyflowing in a countercurrent direction, but may, as an alternative, ifdesired, flow in a co-current direction. The resultant volatilizationproduces a volatile enriched vapor stream which is largely depleted ofoxygen and may, if desired, be delivered to the pyrolysis first reactorwhere it mixes with the non-condensable gases and condensable vaporsproduced in the pyrolysis reactor. There are several benefits of mixingthe streams. This lessens the tendency to form fog which is difficult tocondense. It also helps to purge the materials produced in the pyrolysisreactor. The lower velocity in the vapor space in the pyrolysis reactoralso provides an opportunity to settle out fine carbon that is entrainedfrom the second reactor. The combined stream then exits the pyrolysisreactor to the condenser system. The condensing system will remove thevolatiles along with the condensable vapors produced in the pyrolysisreactor. As a result, a single condensing system suffices for handlingthe two streams, which simplifies operation. The oxygen-depleted airstream will exit the condensing system with the non-condensable gasesgenerated in the pyrolysis reactor. As an alternate, the oxygen-depletedair and volatile stream could be segregated and routed to a separatepurge as shown by co-current operation shown in FIG. 3. This wouldenable separate condensation of the volatiles. If desired, a gasanalyzer, such as a gas chromatograph, an infrared sensor or a suitablecombustibles measuring device may be employed to analyze the gas exitingthe second reactor to determine the oxygen content and the concentrationof other species such as alkylated benzenes and other high-boilingvolatiles.

The recycled carbon black introduced into the second reactor from thefirst reaction may have an average size of about 100 to 25000 micronsand preferably about 50 to 5000 microns and will be reduced through themechanical deagglomeration to an average size of about 20 to 200 micronsand preferably about 5 to 100 microns.

The present invention creates a high temperature zone in the secondreactor as a result of the reaction of the oxygen in the air stream withthe volatiles in the carbon that is entering recycled carbon black. Thehigh temperature zone raises the vapor pressure of the volatiles andenables them to be stripped into the countercurrent flow of air in theintensely turbulent mechanically agitated contactor. The hightemperature zone is relatively short in length and short in contact timedue to the intense turbulent contact and the countercurrent flow. Thisserves to resist undesired degradation reactions. A further benefit ofplacing the high temperature zone at least partially within themechanical means for deagglomeration is that the portion of the peaktemperature zone which is downstream with respect to the direction offlow of the recycled carbon black preheats the countercurrent air.Upstream of the peak temperature zone, the counter-flow of carbon andoxygen-depleted air preheats the carbon. With both concepts ofpreheating, a more efficient method is provided.

The invention contemplates controlling the stripping of the volatilesfrom the recycled carbon black by exercising control of the ratio of airto entering carbon. The weight of air is measured directly and thequantity is set against an estimate of the flowing carbon. The flowingcarbon weight is estimated from the expected yield of carbon from thetire shreds together with an estimate of the flowing tire shredsentering the pyrolysis reactor. The weight flow of air will be adjustedto achieve the targeted peak temperature in the second reactor. Thistarget will in turn be adjusted up or down to achieve the targeted levelof volatiles in the carbon collected in the collection bin. An onlinemeasurement by automatic sensors of the gases leaving the second reactorcan also be used to adjust air flow rate. The ratio of air to carbondetermined on the basis of this procedure may be about 0.02 to 0.3 andpreferably is about 0.04 to 0.2. An increase in this ratio lowersvolatiles as it raises the peak temperature. The volatiles may bemeasured directly with an offline test or monitored continuously by wayof automatic sensors with the ratio being adjusted as desired.

Referring to FIG. 1, there is shown a pyrolysis reactor 2 which receivesrubber tires or tire shreds 4 and under the influence of heat such asmight be present in a conventional pyrolysis reactor such as, forexample, those disclosed in U.S. Pat. Nos. 6,833,485 and 6,835,861,converts the rubber to carbon particles and other residue. The pyrolysisreactor which may typically operate in a temperature range of about 350°F. to 1050° F. and preferably about 350° F. to 850° F. causes theelastomers, such as polybutadiene, to be broken into smaller organiccomponents. The primary solid left behind is the mixture of virgincarbon blacks used in the original tire recipe. The virgin carbon blackin the solid recycled black carbon largely retains its basic propertiesand can be reused as a reinforcing agent in polymer and elastomerrecipes. The materials emerging from the exit end 8 of the pyrolysisreactor 2 for convenience of reference herein will be referred to as“recycled carbon black”. The particle size of the recycled carbon blackemerging from the pyrolysis reactor 2 will typically be an average sizeof about 100 to 25000 microns and preferably about 20 to 200 microns.

In the form shown in FIG. 1, the recycled carbon black is subsequentlysubjected to turbulent mechanical deagglomeration in a second reactor 10which is operatively associated with first reactor 2. The specific formshown in FIG. 1 has an auger 12 which is disposed within conduit 13 andis inclined at an angle A with respect to the horizontal and slopesupwardly from its entry portion 14 to its exit portion 16. It transportsthe recycled carbon black upwardly. Angle A may be about 1° to 60° andpreferably about 1° to 50°. The auger is rotated at about 20 to 100 rpmand preferably at about 40 to 90 rpm. As the recycled carbon black istransported through the auger 12, it is subjected to turbulent forcewhich deagglomerates the recycled black carbon to an average particlesize of about 20 to 200 microns and preferably about 5 to 100 microns.It is preferred that the deagglomeration reduces the average size of therecycled carbon black by about 40 to 90%. It will be appreciated that,if desired, the other means of mechanical deagglomeration such as airjets causing high pressure air to impinge upon the recycled black carbonor a fluid bed reactor or a high speed rotating device, such as a hammermill, may be employed.

A feature of the present invention in order to provide oxygen has air 20introduced to flow in a countercurrent direction as indicated by arrow Xwithin auger 12 in opposition to the direction of flow of thedeagglomerated recycled carbon black as shown by arrow Y. The air may beintroduced at a temperature of about 50° F. to 500° F. An inert gas suchas nitrogen or carbon dioxide, for example, is preferably introduced at24 as a safety precaution in order to minimize risks of explosionresulting from the carbon particles. This resists a dust explosionoccurring in a carbon collection bin 30. This could occur during anupset in operation or when carbon bins are switched. The inertenvironment is achieved by depleting the air of oxygen by reaction,thereby creating an environment that is primarily inert gas.

The oxygen in the air reacts with organics on the recycled black carbonto evolve heat, which gives a local temperature high enough to achievethe desired degree of volatile removal. Such high temperature isachieved by oxidation of a part of the volatiles by oxygen brought intothe system by the air. The oxygen-depleted air stream then serves as thestripping gas to remove volatiles. For example, a pyrolysis reactor 2emits the recycled carbon black at a temperature of about 350° F. to850° F. The oxygen effect in the second reactor 10 raises thetemperature of the carbon black within a portion of the auger 12 byabout 900° F. to 1200° F. which results in enhanced devolatilization.This high temperature zone is such that the air entering adjacentportion 16 of auger 12 is preheated as it moves in direction X towardthe high temperature zone and as its flow continues to where it isdischarged, serves to preheat the recycled carbon black entering theauger 12 and moving in direction Y. The thus deagglomerated anddevolatilized carbon black is introduced into the carbon blackcollection bin 30 for storage or activated elsewhere for additionalprocessing to remove impurities and further reduce particle size.

Referring to FIG. 2, the primary devolatilization region which is hightemperature zone HT may assume different axial extents within the auger12. In the form illustrated, it may be deemed to extend betweenreference numbers 34 and 36 with the carbon preheat zone CP extendingbetween reference numbers 32 and 34 and the air preheat zone APextending between reference numbers 36 and 38.

Referring to FIG. 1, the emerging volatiles, which includeoxygen-depleted air and with vapors generated in pyrolysis reactor 2 andinert gases which exit through exit 8, may be transported to thepyrolysis reactor 2 for discharge to condenser 22, if desired. A gasanalyzer 39 is operatively associated with the interior of conduit 13 tofacilitate monitoring of the process.

The air having passed through the high temperature zone 34-36 serves topreheat the incoming recycled carbon black material in zone 32-34. Also,the carbon black material moving through auger 12 in the direction ofarrow Y after it passes through the high temperature 34-36 serves topreheat the countercurrent flowing air moving in direction X throughzone 36-38. It is preferred to thermally insulate the exterior of auger12 in the high temperature zone 34-36 and to avoid such insulation inzone 36-38 to facilitate cooling of the carbon black.

Referring now to FIG. 3, there is shown a modified embodiment of theinvention wherein the air 42 from source 20 is introduced into lowerportion 14 of auger 12 and the oxygen-depleted air and volatilesstripped by the present invention emerge from adjacent the upper portion16 of auger 12 as indicated at 44. In this embodiment of the invention,the recycled carbon black would move in the direction of arrow Y and theair would move co-currently in the direction of arrow Z. In this form,the auger is inclined at an angle A which may be about 1° to 60° andpreferably about 1° to 50. This upward tilt serves to provide a seal atthe lower end of the auger 12 by the recycled carbon black. In thisembodiment of the invention, the recycled carbon black and the air wouldbe moving in the same direction Y, Z and pass through the hightemperature zone moving in the same direction. As a result, thepreheating benefits of the countercurrent embodiment of the inventionwould not be obtained.

The non-carbon black materials in the recycled carbon black can beconsidered generally to consist of “ash” and “volatiles”. Ash isprimarily composed of inorganic components present in the feed recipe orformed in the pyrolysis process. It typically amounts to about 10 to 20weight percent of the recycled carbon black. The inorganic compounds actprimarily as diluents so long as the particles are relatively small insize.

The volatiles are primarily organic materials formed from polymers, suchas rubber elastomers and reinforcing tire cord, in the original tirerecipe with some additional materials coming from reinforcing fibersused in tires. A standard test for volatiles involves heating the sampleto 1700° F. with the weight loss being the volatile content. A majorobjective of pyrolysis is reduction of the level of volatiles to a pointwhere the volatiles do not have a negative impact on the quality of therecycled carbon black. As the pyrolysis process proceeds, the volatilesare reduced and the percentage ash increased. The materials included inthe volatile category range from simple fragments of long-chainedelastomers to aromatics formed by rearrangement of these fragments tohighly oxygenated species such as terephthalic acid, for example. Thenature of the intended final use for the recycled carbon black can beinfluential in determining if the volatiles are beneficial to carbonblack reinforcing properties as they can aid the bonding process betweencarbon black and rubber elastomers. Too many of the organics lessen thereinforcing quality of the recycled carbon black. The volatile contentof the recycled carbon black exiting the pyrolysis reactor can exceed30% by weight with a preferred level for the ultimate recycled carbonblack product generally being between about 2 to 10% by weightvolatiles. It is, therefore, desirable to have an efficient means ofremoving volatiles from the recycled carbon black emerging from thepyrolysis reactor.

Due to heat transfer and diffusion limits, it is more difficult todevolatilize large particles of recycled carbon black than smaller ones.For example, the compositions of ⅝-inch shreds taken from a pneumaticvehicle tire and 1¼-inch shreds taken from a pneumatic vehicle tire areshown in Table 1. The removal of volatiles is measured by the increasein ash weight percentage. As volatiles are removed, the ash weightpercentage increases. The ash content is always lower in the finerparticles. The difference in ash between the less than 250 micron andgreater than 4800 micron particles indicates that the coarse particleshave twice the volatile percentage as do the fine particles.

TABLE 1 Particle Size ⅝-inch 1¼-inch Shreds Shreds Ash Ash Weight %Weight % Less than 250 microns 16.5 19.0 Between 250 microns and 2400microns 14.0 14.1 Between 2400 microns and 4800 microns 9.8 10.4 Greaterthan 4800 microns 7.7 9.8 Total Sample Mass 13.2 15.1Also, the volatiles were much smaller in the small particles than in thelarger particles. The major change in volatiles, as measured by the risein ash, results from the fact that for small particles both heattransfer and diffusion vary inversely with the square of the particlesize. A sphere of 200 microns takes only 1% as long as a sphere of 2000microns to achieve the same degree of devolatilization. Similarly, asphere of 50 microns takes only 1% as long as a sphere of 500 microns toachieve the same degree of devolatilization. This pattern is evident inthe data of Table 1. The deagglomeration achieved in the second reactor14 enables very fast devolatilization while resisting coke formation inthe high temperature zone HT (34-36) of the second reactor 14.

The present invention permits operation of the pyrolysis reactor at alower temperature thereby effecting a savings in energy costs and otherbenefits. The exit temperature in the pyrolysis reactor preferably is inthe range of about 350° F. to 850° F. while achieving desireddevolatilization at that stage of the processing.

A Department of the Interior report in 1969 (Wolfson, Beckman, Waltersand Bennett, Destructive Distillation of Scrap Tires, Bureau of MinesReport of Investigation 7302, 1969) stated that for pyrolysis at 930°F., the basic split on a weight basis involves the following materials:(1) heavy oil, 45%; (2) light oil, 4%; (3) gas, 5%; (4) carbon, 42%. Theheavy oil splits into several fractions, with the largest fraction beingneutral oil at 56% which, in turn, splits into the following breakdowns:(a) aromatics, 51%; (b) paraffins and non-aromatic rings, 31% and (c)olefins, 18%. The breakdown of aromatics identified in the heavy oil ona weight basis is set forth in Table 2.

TABLE 2 Alkyl benzenes 19% Styrene 2% Alkyl styrenes 11% Phenols 1%3-ring aromatics 2% Biphenyl, acenaphrene 6% Alkyl naphthalenes 8%Indene 7% Other heterocyclic 10%At higher temperatures, the major change is increased aromatics alongdecreased paraffins and non-aromatic rings. The significance ofaromatics is that they readily bond to carbon black and are moredifficult to devolatilize.

In evaluating the energy consumption regarding deagglomeration, forlarge starting sizes in the neighborhood of 5000 microns being reducedin size to under 200 microns, the energy required is approximatelyproportional to the square of the final size desired. For example, for asize reduction from 5000 microns, which is approximately one fifth of aninch to 100 microns, the energy is only about 4% of the energy requiredto reduce the size to 20 microns. As a result, the present systempreferably involves a reduction to about 20 to 200 microns from startingsizes in the range 50 to 5000-microns.

Tests have indicated that the reduction in volatiles in the presentsystem is not a simple stripping of the volatiles into a gas stream,such as nitrogen, but rather is enabled by the temperature rise thatoccurs due to the reaction of the oxygen in the air with volatiles.

The combination of the deagglomeration and air injection of the presentinvention generally results in a reduction in volatiles in the recycledcarbon black from exit volatile level at the pyrolysis reactor 2 to exitarea 16 of auger 12 of about 15 to 30% and preferably about 2 to 10% andmost preferably about 4 to 7%.

The preferred residence time of the recycled carbon black in the hightemperature zone HT (34-36) is about 1 to 60 minutes, preferably about 5to 20 minutes, and most preferably about 5 to 10 minutes. It should beresident in this zone for a sufficiently long time to increase theamount of material volatilized, while not being so long as to convertspecies like terephthalic acid to coke or to convert the non-volatilesulfur-containing compounds like zinc sulfide to gaseous species such asSO₂, COS or H₂S. It is recognized that the actual time the carbon blackis in the high temperature zone of the second reactor 14 issignificantly less than the total time in the second reactor, typicallybeing in the range of 10% to 35% of the total time. For a sufficientlyhigh temperature, even refractory species such as terephthalic acid canbe removed and at even high temperatures, some of the sulfur compoundscan be degraded, if desired.

It will be appreciated that the present invention provides aneconomical, improved method and associated apparatus for efficientlycontrolling the volatile content of carbon black processed from recycledcarbon black created by an initial pyrolysis process.

Whereas particular embodiments of the invention have been described forpurposes of illustration, it will be evident to those skilled in the artthat numerous variations of the details may be made without departingfrom the invention as defined in the appended claims.

The invention claimed is:
 1. Apparatus for removing volatiles fromcarbon black comprising a first reactor for creating recycled carbonblack, a second reactor for receiving recycled carbon black from saidfirst reactor, mechanical deagglomerating apparatus disposed within saidsecond reactor for deagglomerating said recycled carbon black to producedeagglomerated recycled carbon black, and air flow introductionapparatus disposed in communication with said second reactor fordelivering a current of air to said deagglomerated recycled carbon blackto establish a high-temperature zone and increase the temperature ofsaid deagglomerated recycled carbon black and release volatilestherefrom.
 2. The apparatus of claim 1 including said first reactorbeing a pyrolysis reactor.
 3. The apparatus of claim 2 including saidsecond reactor structured to receive said recycled carbon black in asize of about 100 to 25000 microns.
 4. The apparatus of claim 2including said air flow introducing apparatus structured to providecountercurrent air flow with respect to the direction of flow of saidrecycled carbon black.
 5. The apparatus of claim 2 including said airflow introducing apparatus structured to provide co-current air flowwith respect to the direction of flow of said recycled carbon black. 6.The apparatus of claim 2 including said mechanical deagglomeratingapparatus structured to reduce said recycled carbon black to a particlesize of about 50 to 5000 microns.
 7. The apparatus of claim 1 includingsaid second reactor having thermal insulation around the portion thereofwherein said deagglomerated recycled carbon black is subjected toelevated temperature in said high temperature zone.
 8. The apparatus ofclaim 2 including said mechanical deagglomerating apparatus structuredto reduce said recycled carbon black to a particle size of about 20 to200 microns.
 9. The apparatus of claim 1 including an inert gas supplyfor introducing inert gas into said second reactor.
 10. The apparatus ofclaim 1 including an auger to effect said mechanical deagglomeration.11. The apparatus of claim 10 including said auger being inclinedupwardly from entry to exit.
 12. The apparatus of claim 11 includingsaid auger being upwardly sloped at an angle of about 1° to 60°.
 13. Theapparatus of claim 12 including said auger being structured to rotate atabout 20 to 100 rpm.
 14. The apparatus of claim 12 including said airflow introducing apparatus structured to introduce air at an upperportion of said auger.
 15. The apparatus of claim 1 including saidsecond reactor being structured to reduce said volatiles to about 2 to10% of said recycled carbon black.
 16. The apparatus of claim 12including a conduit for delivering at least a portion of said volatilesremoved from said recycled carbon black to said first reactor.
 17. Theapparatus of claim 16 including a gas analyzer operatively associatedwith said conduit for determining the content of said volatiles.
 18. Theapparatus of claim 1 including said second reactor having a firstpreheat zone for preheating said air before said air enters said hightemperature zone.
 19. The apparatus of claim 18 including said secondreactor being structured to have recycled carbon black which has passedthrough said high temperature zone preheat said air.
 20. The apparatusof claim 19 including said second reactor being structured to have airwhich has passed through said high temperature zone preheat saidrecycled carbon black.
 21. The apparatus of claim 1 including saidsecond reactor structured to effect by said mechanical deagglomerationapparatus about 40 to 90% reduction in the average recycled black carbonsize.
 22. The apparatus of claim 1 including said second reactor havingthermal insulation disposed around said high temperature zone.
 23. Theapparatus of claim 22 including said second reactor being substantiallydevoid of thermal insulation downstream of said elevated temperaturezone with respect to the direction of flow of said recycled carbon blackparticles.